Switch blade and process



H KRANTZ.

SWITCH BLADE AND PROCESS.

APPLICATION FILED JUNE 16, 1917- L 2 9 1 fi 0 Bu D d e t n N a P 2 SHEETS-SHEET I.

H. KRANTZ.

SWITCH BLADE AND PROCESS.

APPLICATION FILED JUNE 15, I917. 1,399,119 1 Patented. Dec. 6, 192L 2 SHEETS-SHEET 2- 8 wuewtoz it'll with lid

all ill TUNING GOMPANY, Ilttt, Uh BROQKLYD YUM.

,. NEW roan, A UllltPURAllllUhl' ft l lll'l'llll' SWl'llfiI-l BLADE AND PEUCESS.

t eater;

To all w from it may concern 7 Be it known that l, l-lnnnur .llinan'rz, residin at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in a Switch Blade and lowing is a specification.

This invention relates to a switch blade such as is shown in my copending application Serial No. 1t,l30 filed March 13, 1915, and renewed April 11, 1916, Serial No. 90,519, and also 1n my co ending application Serial No. 85,853 filed arch 22, 1916, and to a process for producing such switch blades.

An object of the present invention is to provide a switch blade which may be pivotally supported intermediate its ends to swing said ends simultaneously for making and breaking engagement with suitably arranged spaced contact members whereby to control a circuit between said contact members.

A further-object is to provide a switch blade as above which is made up of a num ber of separate strips of suitable material bound together to provide a flexible structure the strips being continuous from end to end of the blade and the end edges of the strips collectively providing broad and of ficient contact surfaces for engaging the stationary contacts.

A further object is to provide means to retain the end portions of the strips against undue heating in use, and to retain said end portions against likelihood of becoming distorted or bent. l

A further object is to provide a switch blade made up essentially of a plurality of strips of-suitable material all. of the same size and shape and connected together in such manner as to provide beveled'end contact surfaces for the blade, thus providing high efficiency at small cost, and to connect the blades together so that the bevel pro duced at the ends of the blade is at such an angle as to cause the strips to spread apart as they are moved into engagement with properly arranged stationary contacts, thereby to improve the electrical engagement and to afford a cooling action in use.

A further object is to provide insulating means forsupporting the switch blade in a suitable carrier so that the blade is insulated both from the carrier and from any other tpeciltcatton of letters latent.

Application filed tune it,

Process, of which the fol- I Patented Dec. fi, infill. will. hertal lto. Wallet.

blades which may carrier.

A further object is to provide an improved process to be followed in the manufacture of the switch blade of this invention.

Uther objects and aims of the invention, more or less specific than those referred to above, will be in part obvious and in part pointed out in the course of the following description of the elements, combinations, arrangements of parts and applications of principles, constituting'the invention; and the scope of protection contemplated will be indicated in the appended claims.

in the accompanying drawings which are to be talren as a part of this specification, and in which l have shown merely a preferred form of embodiment of the invention:

Figure l is a diagrammatic view illustrating the switch blade of this invention in association with a pair of stationary contacts, the blade being shown in the oil osition.

1F ig. 2 is a similar view showing the switch blade in the on position, dotted lines illustrating the position and condition just prior to movement into full on position.

lFig. 3 is a in lg. l, the being omitted.

Fig. A is a diagrammatic view illustrating a process of connecting together the several strips comprising the switch blade.

Fig. 5 is a diagrammatic view illustrating the process by means of which opposite end ortlons of the switch blade of Fig. 1 may be bent laterally for improving its functional operation in use.

1F ig. h is a longitudinal sectional View taken upon the plane of line Vll of Fig. 'l' the condition of the blade when in on position being illustrated by dotted lines.

lBig. 7 is a top plan View of the structure shown in Fig. 6, and

be supported by the plan view of the blade shown insulating support or carrier Fig. 8 is a diagrammatic view illustrating :1

a modification.

Referring to the drawings for describing in detail the structure which is illustrated therein, and referring first to the structure shown in F i s. l to A, the reference characters L and indicate opposite spaced stationary contacts, and the reference character indicates the switch blade of this invention pivotally supported a at 1 between said stationary contacts.

1 ll l The switch blade H is laminated, being made up of. any desired number of thin metallic stripsas those designated 2, 3, 4. and 5 in Fig. 4. These are all of the same length and are arranged face to face each slightly in advance of the other longitudinally 1n echelon relation so as to collectively define bevel contact surfaces 28 at the opposite ends of the switch blade. The bevels at the opposite ends of the switch blade, by this arrangement, are also faced in opposite directions and are in parallel planes so as to correctly cooperate with the stationary contacts of the respective ends.

The angle of bevel is of course determined by the distances of advance of each plate with respect to its neighbor and preferably this distance is made so as to provide a bevel of such angle relativel to the stationary contacts that the respectlve end of the outermost strip will be the first to engage the contact. The end of the next adjacent strip will engage the contact when the blade has been slightly further rotated thus causin the first and second strips to separate slight y at their ends and provide an air space between them. The end of the first strip will also drag slightly along the surface of the stationary contact before the second strip touches.

Further rotation of the blade brings the third strip against the contact so separating it from the first and second strips and dragging the first and second strips along the stationary contact. Bythe time the ends of all the strips are in enga e'ment with the contact they are all spaced rom their neighbors as clearly shown in Fig. 2, of course, at both ends of the switch blade alike, and all have been caused to drag along the surface of the contact. The air spaces provided between the strips maintaining them comparatively cool at all times when in engagement with the contact and the dragging or rubbing action materially increases the efficiency of the electrical connection.

The various strips comprising the switch blade may be held together and supported in any suitable carrier such as that shown at 6.

A simple and practical process .by means of which the strips may be properly connected together is illustrated in Fig. 4 in which the several strips 2, 3, 4 and 5 are shown each to have an aperture 7 therein.

These apertures are made successively nearer to one end of the strips so that when brought into alinement to receive the rivet 8 the strips will stand in echelon relation.

In some instances it is desirable to increase the efficiency of the blade, and in such instances afurther operation may be impressed upon the assembled strips, as shown in Fig. 5. This includes holding the blade between a pair of jaws 9 so that opposite end portions of the blade project from between said jaws, 'and then, bv the use of suitable levers 10 and 11, bending over the projecting ends of the blade in opposite directions so that they are caused to stand permanently in angular relation to the main lntermediate portion of the blade.

This bending over of the end portions of the blade in the manner indicated has the desirable effect of causing the end portions of the strips comprising the blade to become spread apart in fan like relation so that permanent air-spaces are formed between them. This is brought about by reason of the fact that the strip farthest from the levers bends over a relativel sharp corner or anvil 12 while each succeecfin strip bends over a corner which is formed its neighbor and which is therefore successively less sharp.

In Fig. 6 a complete switch blade is illustrated u on which the ste of Fig. 5 has been perfbrmed, and in this figure the permanent air-spaces between the end portions of the strips are clearly apparent, as as 13. By this arrangement a so the bevel at the ends of the blade may be arranged at such angle as to cause all of the strips, to engage and leave the stationar contacts substantially at the same time if desired without losing any of the cooling action referred to with regard to the tructure of Fig. 1. The permanent bend in the blade also affords a desirable flexing action of the blade in operation since it makes each strip more independent of its neighbors;

As shown in Figs. 6 and 7 the complete switch blade may include a pair of relatively heavy strips 14 arranged one at each side of the group of thin strips. These are intended to reinforce and stiffen the thin strips and to prevent likelihood of their becomin incorrectly bent or distorted during han ling or use.

A second pair of relatively heavy strips,

as 15, are also arranged one upon the outer surface of each of the stri s 14. These are intended to carry the sparl; heads 16 one at each end of the switch blade beyond the apex of the bevel, said heads 16 being arranged normally to stand ina plane be 0nd the bevel surface so as to be the last to eave the stationary contacts when the switch is being moved to the off position. They are intended to resist the heat of the momentary are which is usually incident to the breaking operation.

All of the thin strips and heavy stri s are bound together metal to metal and hel tight by one or more rivets 17 which extend through mating apertures therein so that the blade becomes in effect a single integral 'metallic element.

The switch blade carrier illustrated in Figs. 6 and 7 comprises a pair of opposite clamp plates 18 held in position by rivets or ltd lltl

lib

nearer blade. fhe'switch blade is eectually insulated from the carrier by means of a pair of insulating plates 20 interposed between the clamp plates 18 and t e opposing surfaces of the switch blade, and a pair of insulatingsleeves 21- which surrouind the rivets l9. lln order to prevent ossible creepage from the switch blade to tlh e carrier the apertures in the insulating plates 20, where the rivets pass through, are enlarged and the opposite ends of the insulating? sleeves 21 are continued therethrough tlush with the outer surfaces of the plates 20, and ether insulating plates as 22 are amen ed between the clamp plates 18 and the insulating plates 20 having parts, as at 23, disposed to bridge the joints where the sleeves 2f the through the plates 20. This is accomp i'shed by making the rivet receivin apertures in the plates 22 smaller than t e apertures in the plates 20 so that they are of a site to receive only the rivets. This arrangement also disposes the parts 23 of the plates 22 in a position to receive direct pressure from the clamp plates it when the rivets 19 are driven tight. Aidjacent portions of the plates 22 are at the same time clamped tightly against the end till tilt

tilt

lid

surfaces of the sleeves 21 thus efiectually closing any possibility of leakage to the rivets and carrier along the joint between the plates 22 and the ends of the sleeves. lit will be noted in this connection that the tightness of the joint between the sleeves and the walls of the apertures in the plates 20 is dependent upon the relative sizes of said sleeves and apertures and unless the sizes are very accurate an opening would be left through which an arc might be formed directly from the switch blade to the clamp plates of the carrier were it not for the interposition of the plates 'lfhe' interposition of the plates 22 not only closes the direct passage referred to but it effectually seals said passage as above described.

ltven if the joint between the plates 22 and the end surfaces of the sleeves is not absolutely tight it will be seen that said plates change the possible straight arcing path between the blade and the carrier to an angular path of double length from the switch blade outwardly to the inner surface of the plate 22 and then in a right-angular direction across the end of the sleeve to the rivet.

Each of the insulating plates 20 and 22 are extended at their ends, as at 2t, beyond the adjacent edges of the clamp plates 18 so as to prevent likelihood of an are between the switch bladeand the carrier in these localities.

the insulating plates 20, at their ends nearest to the respective contacts L and G, are preferably further extended so as to provide portions, as at 25, disposed to interpose themselves forpreventing likelihood of an t5 are from the contacts es'the blade swings to of strips arranged face to switch blade,

oil, position. This is in connection with the live side of the circuit.

lln the modification Fig. 8, is illustrated a switch blade made up of thin strips, 26, all of equal length. These are bent, as at 27, so as to provide air-spaces between the end portions thereof but each strip is bent independently before being assembled and thus the air-spaces are of uniform thickness from the points 2? outwardly to the ends of the strips.

The relatively heavy strips it and may be placed in association with this form of switch blade, as illustrated, if desired.

lit should be noted that in some instances the rivets 17 may be omitted if desired and the rivets 19 be depended upon to retain the entire structure assembled. While the rivets 17 may improve the electrical connection between all of the. strips of the switch blade yet their essential purpose is simply to hold said strips assembled while the blade is being handled'prior to and during its connection with the carrier.

The reference character 28 indicates a pivot extension upon the carrier 18 by means of which the carrier is enabled toconstitute a pivotal mounting for the blade.

As many changes could be made in this construction without departing from the scope of the invention as defined in the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative only and not in a limiting sense.

particularly desirable contact carrying the Having thus described my invention, what it claim as new and desire tosecure by Letters Patent is 1. A switch comprising a double ended switch blade, a pair of clamp plates disposed intermediate the ends of the blade between which the blade is held, and insulating plates interposed between the blade and the clamp plates for insulating the blade from the clamp plates and extending beyond the opposite edges of the clamp plates.

2.. it switch blade comprising a plurality face to collectively provide a contact portion for the blade at one end thereof, the end portion of each strip being bent laterally, and the degree of bend of each strip being successively less than the adjacent strip so as to normally dispose said bent portions in outwardly diverging relation to constitute a beveled portion.

3. it switch blade and carrier for the through the switch blade and carrier to corn nect the switch blade with the carrier, and insulating, means for insulating the switch blade from the carrier and connecting member, said insulating means comprising a plate of insulating material interposed between the switch blade andthe carrier, a sleeve of a connecting member extending insulating material surrounding the connect.- ing member and continuing through an opening formed to receive it in the plate of insulating material, together with a second plate of insulating material interposed between the carrier and said first plate of insulating material and between the end of the sleeve and said carrier and bridging the joint between the end of the sleeve and the first plate of insulating material.

4 4. A switch blade, a carrier for the switch blade comprising a pair of plates arranged one at each side of the switch blade, a bolt extending through the switch blade and through said plates to clamp the switch blade between said plates, and insulating means for insulating the switch blade from said plates and bolt, said insulating means comprising a pair of insulating plates arranged one at each side of the blade and between the same and the adjacent clamp plate, a sleeve of insulating material extending through the blade surrounding the bolt and having its end portions continued through apertures formed to receive them in said insulating plates, and other insulating plates interposed to bridge the joint between the end portions of the sleeve and the adjacent walls of the apertures in the first'insulating' plates.

5. A double ended switch blade, a carrier therefor comprising a pair of'clamp plates between which the blade is held, the carrier being arranged'intermediate the ends of the blade sothat the opposite ends of the blade project therefrom, and insulating plates interposed between the switch blade and said clamp plates for insulating the switch blade from the clamp plates, and said insulating plates having portions projecting beyond the opposite marginal edges of the clamp plates for the purpose described.

6. A switch blade comprising a main portion and an end portion, and the end portion comprising a plurality of se arate parts arranged to collectively provi e a contact portion at the end of the blade, and said end parts normally projecting from the main portion in outwardly diverging relation to constitute a beveled portion.

In testimony whereof I ailix my signature in the presence of two witnesses.

J. L. KoLLE, S. L. Wnrrnoox. 

